Less than two years after researchers at the University of Exeter in the United Kingdom warned that the world was approaching multiple climate tipping points, a new report released Monday indicates that one such “point of no return” has already been crossed. The report highlights that warm-water coral reefs are experiencing unprecedented dieback due to rising global temperatures.
Surging global temperatures, particularly in recent years, have led to a widespread decline in coral reef systems. The worst bleaching event on record occurred since 2023, with over 84% of the world’s reefs affected. According to the Global Tipping Points Report 2025, the central estimate of the temperature threshold for coral reefs—1.2°C of global warming—has already been exceeded, as planetary heating now stands at approximately 1.4°C above preindustrial levels.
The warming waters have caused extensive coral bleaching, which threatens nearly a million marine species that depend on these ecosystems for survival. The report emphasizes that unless global mean surface temperatures are reduced to 1.2°C (and eventually to at least 1°C) as quickly as possible, warm-water coral reefs will not be retained on a meaningful scale. It also suggests that minimizing non-climatic stressors, especially through improved reef management, could enhance the resilience of coral ecosystems under minimal temperature exceedance.
The loss of coral reefs has far-reaching consequences, including leaving coastal communities vulnerable to storm surges, exacerbating overfishing by depriving fish of breeding habitats, and impacting thousands of jobs and billions of dollars in reef tourism annually.
As global leaders prepare for the COP30 climate negotiations, the report underscores the urgency of the situation. Steve Smith, a social scientist at the University of Exeter and lead author of the report, stated, “We can no longer talk about tipping points as a future risk. This is our new reality.”
Climate scientist Bill McGuire emphasized that achieving the 1.2°C target is unlikely, stating, “This is the death knell for most of the world’s stupendous reef communities.” He warned that other tipping points will follow if global temperatures continue to rise.
The report identifies several additional climate tipping points that remain imminent, including large-scale degradation of the Amazon rainforest, which could weaken global climate regulation and accelerate biodiversity loss; the melting of mountain glaciers such as Áakʼw Tá Hít in Alaska; and the Atlantic Meridional Overturning Circulation (AMOC), whose likelihood of reaching a tipping point increases with global temperature rise.
Without rapid cuts to greenhouse gas emissions, the report warns that the upper temperature threshold for coral reefs—1.5°C—will likely be reached within a decade. Tim Lenton of the University of Exeter’s Global Systems Institute told The Guardian, “We are going to overshoot 1.5°C of global warming probably around 2030 on current projections.”
Manjana Milkoreit, a co-author of the report and political scientist at the University of Oslo, noted that while the knowledge to prevent further tipping points exists, it requires governance structures that match the scale of the challenge. She said, “What we need is a kind of governance that matches the nature of this challenge.”
The report also highlights potential “positive tipping points” that could drive rapid reductions in greenhouse gas emissions. These include the widespread adoption of regenerative agriculture, the acceleration of electric vehicle and solar power use, and the spread of climate litigation and nature-positive initiatives. The report notes that falling costs of solar panels and batteries, along with increased deployment, have created a self-reinforcing cycle of adoption.
Lenton added that “the race is on to bring forward these positive tipping points to avoid what we are now sure will be the unmanageable consequences of further tipping points in the Earth system.”
Global progress toward transitioning from fossil fuels and expanding renewable energy has accelerated worldwide, though the U.S. has lagged under President Donald Trump. Recent legislation has imposed fees on solar and wind development, boosted drilling on public lands, and allocated $625 million to coal projects, according to reports.
The Global Tipping Points Report 2025 was released four weeks ahead of the COP30 climate summit in Belém, Brazil. At the conference, policymakers will be encouraged to contribute to the Granary of Solutions—a repository of scalable, replicable tools aligned with the Paris Agreement—to trigger positive tipping points and drive transformative change.
Mike Barrett, chief scientific adviser at the World Wide Fund for Nature and a co-author of the report, urged global leaders to demonstrate political courage and cooperation during the negotiations. “Countries must show the political bravery and leadership to work together and achieve them,” he said.
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